<template>
  <div :class="[prefixCls]" v-click-outside="onClickoutside" @mouseenter="handleMouseenter" @mouseleave="handleMouseleave">
    <div :class="relClasses" ref="reference" @click="handleClick" @contextmenu.prevent="handleRightClick">
      <slot></slot>
    </div>
    <transition name="transition-drop">
      <Drop :class="dropdownCls" v-show="currentVisible" :placement="placement" ref="drop" @mouseenter.native="handleMouseenter" @mouseleave.native="handleMouseleave" :data-transfer="transfer" :transfer="transfer" v-transfer-dom>
        <slot name="list"></slot>
      </Drop>
    </transition>
  </div>
</template>
<script>
import Drop from '../select/dropdown.vue';
import clickOutside from '../../directives/clickoutside';
import TransferDom from '../../directives/transfer-dom';
import { oneOf, findComponentUpward } from '../../utils/assist';

const prefixCls = 'ivu-dropdown';

export default {
  name: 'Dropdown',
  directives: { clickOutside, TransferDom },
  components: { Drop },
  props: {
    trigger: {
      validator(value) {
        return oneOf(value, ['click', 'hover', 'custom', 'contextMenu']);
      },
      default: 'hover'
    },
    placement: {
      validator(value) {
        return oneOf(value, ['top', 'top-start', 'top-end', 'bottom', 'bottom-start', 'bottom-end', 'left', 'left-start', 'left-end', 'right', 'right-start', 'right-end']);
      },
      default: 'bottom'
    },
    visible: {
      type: Boolean,
      default: false
    },
    transfer: {
      type: Boolean,
      default() {
        return !this.$IVIEW || this.$IVIEW.transfer === '' ? false : this.$IVIEW.transfer;
      }
    },
    transferClassName: {
      type: String
    },
    stopPropagation: {
      type: Boolean,
      default: false
    },
    // 4.0.0
    capture: {
      type: Boolean,
      default() {
        return !this.$IVIEW ? true : this.$IVIEW.capture;
      }
    }
  },
  computed: {
    transition() {
      return ['bottom-start', 'bottom', 'bottom-end'].indexOf(this.placement) > -1 ? 'slide-up' : 'fade';
    },
    dropdownCls() {
      return {
        [prefixCls + '-transfer']: this.transfer,
        [this.transferClassName]: this.transferClassName
      };
    },
    relClasses() {
      return [
        `${prefixCls}-rel`,
        {
          [`${prefixCls}-rel-user-select-none`]: this.trigger === 'contextMenu'
        }
      ];
    }
  },
  data() {
    return {
      prefixCls: prefixCls,
      currentVisible: this.visible
    };
  },
  watch: {
    visible(val) {
      this.currentVisible = val;
    },
    currentVisible(val) {
      if (val) {
        this.$refs.drop.update();
      } else {
        this.$refs.drop.destroy();
      }
      this.$emit('on-visible-change', val);
    }
  },
  methods: {
    handleClick() {
      if (this.trigger === 'custom') return false;
      if (this.trigger !== 'click') {
        return false;
      }
      // #661
      const $parent = this.hasParent();
      if (!$parent) this.currentVisible = !this.currentVisible;
    },
    handleRightClick() {
      if (this.trigger === 'custom') return false;
      if (this.trigger !== 'contextMenu') {
        return false;
      }
      this.currentVisible = !this.currentVisible;
    },
    handleMouseenter() {
      if (this.trigger === 'custom') return false;
      if (this.trigger !== 'hover') {
        return false;
      }
      if (this.timeout) clearTimeout(this.timeout);
      this.timeout = setTimeout(() => {
        this.currentVisible = true;
      }, 250);
    },
    handleMouseleave() {
      if (this.trigger === 'custom') return false;
      if (this.trigger !== 'hover') {
        return false;
      }
      if (this.timeout) {
        clearTimeout(this.timeout);
        this.timeout = setTimeout(() => {
          this.currentVisible = false;
        }, 150);
      }
    },
    onClickoutside(e) {
      this.handleClose();
      this.handleRightClose();
      if (this.currentVisible) this.$emit('on-clickoutside', e);
    },
    handleClose() {
      if (this.trigger === 'custom') return false;
      if (this.trigger !== 'click') {
        return false;
      }
      this.currentVisible = false;
    },
    handleRightClose() {
      if (this.trigger === 'custom') return false;
      if (this.trigger !== 'contextMenu') {
        return false;
      }
      this.currentVisible = false;
    },
    hasParent() {
      //                const $parent = this.$parent.$parent.$parent;
      const $parent = findComponentUpward(this, 'Dropdown');
      if ($parent) {
        return $parent;
      } else {
        return false;
      }
    }
  },
  mounted() {
    this.$on('on-click', key => {
      if (this.stopPropagation) return;
      const $parent = this.hasParent();
      if ($parent) $parent.$emit('on-click', key);
    });
    this.$on('on-hover-click', () => {
      const $parent = this.hasParent();
      if ($parent) {
        this.$nextTick(() => {
          if (this.trigger === 'custom') return false;
          this.currentVisible = false;
        });
        $parent.$emit('on-hover-click');
      } else {
        this.$nextTick(() => {
          if (this.trigger === 'custom') return false;
          this.currentVisible = false;
        });
      }
    });
    this.$on('on-haschild-click', () => {
      this.$nextTick(() => {
        if (this.trigger === 'custom') return false;
        this.currentVisible = true;
      });
      const $parent = this.hasParent();
      if ($parent) $parent.$emit('on-haschild-click');
    });
  }
};
</script>
